Button actuated pressure release and locking devices for pressure cookers

ABSTRACT

A pressure cooker handle assembly that relieves pressure in the cooker and unlocks the lid by pushing a single button twice. The button includes a tab that directly activates a pressure relief valve to release the pressure and a leg that depresses a stopbar to unlock the lid. Pressing of the button a first time releases the pressure in the cooker, but does not unlock the lid. A latch system prevents the cooker from again building pressure once the button is pressed. When the button is pressed a second time the leg depresses the stopbar to unlock the lid from the cooker

FIELD OF INVENTION AND BACKGROUND OF INVENTION AND PRIOR ART

[0001] This invention relates to a safety pressure release mechanism anda safety lock for pressure cookers.

[0002] The prior art discloses a variety of locking and pressure releasemechanisms for pressure cookers. For example, Sebillotte U.S. Pat. No.4,620,643 discloses a manually actuated safety device to prevent closureof a pressure valve if the handles of the cooker are not in the closedposition and prevent opening of the lid when both the handles and thepressure valve are in a closed position. Chen U.S. Pat. No. 4,294,377discloses a coupling steel ring and spring band on the cover of apressure cooker that prevents the pressure in the cooker from exceedinga predetermined saturated pressure, thus keeping the pressure in thecooker constant. Brewer U.S. Pat. No. 4,840,287 discloses a pressurecooker locking mechanism having a camshaft assembly that prevents thecooker lid from being locked if the camshaft is not fully extended; apressure responsive safety mechanism is also provided to prevent theopening of the locking mechanism when the cooker is under pressure.

[0003] Additional examples include Moucha U.S. Pat. No. 4,932,550, whichdiscloses an interlock structure that prevents pressurization of thecooker if the lid is not securely attached to the cooker and preventsremoval of the lid until the pressure in the cooker has dropped below apreset maximum. Seethaler U.S. Pat. No. 3,559,839 discloses a pressurecooker that is opened and closed by the rotation of upper and lowerhandles; the lower handle has a heat expandable element that urges alock pin into a slot in the upper handle so that the cooker cannot beopened until the temperature has been lowered to a selected value andthe lock pin has retracted from the slot.

[0004] Further, in Walker U.S. Pat. No. 4,103,801 the pressure cookerhas a slidably mounted, manually operated lock member that must beunlocked in order to open the cover. Pressure in the cooker urges thestem of a sealing plug in the cover of the cooker upwardly and intoengagement with the lock member when the handles are properly alignedand pressure builds in the cooker, thus preventing the cooker from beingopened until the pressure decreases. A similar safety button is shown inthe lid of Chen U.S. Pat. No. 6,257,124; when the cooker is underpressure, the safety button is positioned such that the lid cannot bemanually opened. Zabel U.S. Pat. No. 4,257,394 discloses locking meansconnected with flanges in the lid and cooker body such that the lid willnot rotate when the cooker is pressurized; a spring actuated reliefvalve is connected to a timer so that pressure is maintained in thecooker for a predetermined period of time after which the lid can beremoved. In Demeyere U.S. Pat. No. 4,735,192 the cooker cannot be openeduntil the operator manipulates a knob, the movement of the stem of whichallows a pin or peg to push a seal ring away from its seats, thusdepressurizing the cooker and allowing the lid to be removed.

[0005] In Mendonca U.S. Pat. No. 6,105,808 a pop up valve prevents thelid from being turned to open the cooker when it is under pressure; thepop up valve also prevents pressure from building in the cooker if thelid is not properly installed on the cooker. Similarly, in Barrena U.S.Pat. No. 6,135,013 a valve remains in the up position when the cooker ispressurized and prevents a locking member from being released, and, inElorza U.S. Pat. No. 6,067,896 a valve must drop in order to permit thelid to be opened. In Chameroy U.S. Pat. No. 5,370,259 the lid is sealedto the cooker via lock jaws; pressure developed during cooking istransmitted to internal faces of the lid, causing the lid and lock jawsto be forced together so that the lid cannot be removed until theinternal pressure is reduced, and, in Chameroy U.S. Pat. No. 5,370,257,the cooker cannot be opened under pressure because a flow limitingvalve, then in an up position, prevents the sliding of a latch or boltthat is necessary to open the cooker.

[0006] None of the prior art devices or patents, however, appear toprovide: a simple guided means to reliably and safely install and lockthe lid in sealing engagement on the cooker; simple, single-button meansto relieve the pressure in the cooker, prevent the cooker fromre-pressurizing, and unlock the lid of the cooker; means toautomatically reset the various safety and convenience features of thecooker during the installation and removal of the lid of the cooker;positive latch means that allow an operator to perform other tasks whilethe cooker is depressurizing; means to automatically lock the lid on thecooker as it is being placed on the cooker; and means to make such a thecooker without the use of timers, pressure sensitive materials or parts,heat sensitive materials or parts, or moving parts that are preset topredetermined tolerances, pressure levels, heat levels, or weight levelsso that they operate properly during pressurization and depressurizationof the cooker.

SUMMARY OF INVENTION

[0007] The inventive cooker handle assembly contains an automaticpressure release system that allows the operator to press a button afirst time—i.e., down to a first level—in order to relieve the pressurein the cooker. Once the button is pressed down to the first level, alatch arrangement prevents the button from returning to its up positionand, thus, prevents pressure from again building in the cooker. Thelatch arrangement must be reset in order to allow pressure to againbuild in the cooker, and, in order to reset the latch arrangement, thelid must be removed from, and then replaced on, the pot. Thus, theoperator need not tend the cooker or continue to press the button inorder to fully depressurize the cooker, but, may, instead perform othertasks while the pressure is being relieved.

[0008] Nevertheless, when the button is pressed to the first level, thelid is still locked on the pot and cannot be removed. In order to removethe lid from the pot, the same button must be pressed a second time, ordownward to a second level, and held in the second position while thelid is removed. Premature removal of the lid from the pot is resisted byflanges on the lid and pot. The flanges are held tightly together whenthere is pressure in the cooker, which makes it difficult to rotate thelid off of the pot while the cooker is pressurized. The lid may beeasily removed, however, when the cooker is depressurized, and theflanges are not as tightly held together.

[0009] The inventive handle assembly has upper and lower locking handlesthat are rotated into and out of alignment in order to, respectivelylock and unlock the lid to the pot of the cooker. The upper handle isattached to the lid. The lower handle is attached to the pot. When thelid is rotated on the pot, a guide groove and spring-biased guide postin the handle assembly cooperate to guide the lid into a locked andsealed position on the pot and, simultaneously, set the latcharrangement so that pressure can build in the cooker. In addition, asthe lid is being rotated on the pot, a spring-biased stopbar in thelower handle is pressed downward into a slot in the lower handle,allowing the upper handle and lid to rotate to the sealed position onthe pot. However, when the lid reaches its sealed position, thespring-biased stopbar pops up into a slot in the upper handle and locksthe lid on the pot.

[0010] The guidepost that guides the lid into a locked and sealedposition is part of a lock guide that is housed and secured in aninternal cavity in the upper handle of the cooker. The lock guide has anoutward extending spring-biased spring post, an inward extending pushpost, and laterally extending latch dogs, as well as the downwardextending guidepost. The downward extending guidepost extends downbeyond the bottom of the upper handle and is aligned above andcooperates with the guide groove that is formed in the lower handle. Theinward extending push post is aligned with a hole in the rim of the pot.

[0011] The upper handle also has an upper opening that receives andhouses a button that is used to activate various features of theinventive handle. The button has, on its lower side, a downwardextending, rounded tab that is aligned generally above a plunger or pinof a pressure relief valve that is installed in the lid. The button alsohas flexible, downward extending legs. The downward extending legs havelatch arms that extend laterally from the sides of the legs. One of thedownward extending legs of the button is longer than the other leg. Thelonger leg of the button is aligned immediately above the stopbar in thelower handle.

[0012] As the lid is rotated on the pot, the guidepost of the lock guideslides along a curved edge of the guide groove. As the guidepost slidesalong the curved edge of the guide groove, the lock guide in the upperhandle is forced outward against the bias of the spring on the springpost of the lock guide. When the lid is fully rotated into its sealedposition on the pot, the lock guide is positioned such that itslaterally extending latch dogs are aligned below the laterally extendinglatch arms on the downward extending legs of the button.

[0013] When the button is pressed down the first time, or to its firstlevel, the latch arms on the legs of the button are forced around andunder the latch dogs of the latch guide and the downward extending,rounded tab of the button contacts and moves the pin or plunger of thesafety relief valve, causing pressurized air and steam air to beginescaping from and depressurizing the cooker. In this position, the latchdogs of the latch guide are directly above the latch arms of the legs ofthe button and block the upward movement of the latch arms on the latcharms, thus preventing the button from returning to its up position and,in turn, preventing the rounded tab from moving out of contact with thepin or plunger of the safety relief valve. Accordingly, when the buttonis pressed once and is in its first position, the safety relief valveremains activated and does not permit pressure to be rebuilt in thecooker.

[0014] After the cooker is depressurized, the button is pressed downagain, or to its second level. As the button is pressed down farther,the longer leg of the button comes into contact with the stopbar that isextended into the upper handle and pushes the stopbar down into its slotin the lower handle as long as the button is continuously presseddownward at the second level. When the stopbar is pressed down into itsslot, the lid is unlocked and may be rotated back out of sealedengagement with the pot by rotating it in the opposite direction. As thelid is rotated in the opposite direction, the lower surface of the upperhandle prevents the stopbar from moving upward, and the guidepost of thelock guide reverses it path along the curved edge of the guide groove ofthe lower handle. As the guidepost slides along the curved edge of theguide groove, the spring associated with the spring post of the lockguide biases and moves the lock guide inward. As the lock guide movesback inward, the latch dogs move out of alignment with the latch arms ofthe legs of the button and the button is permitted to move back to itsup position. Thus, it is only when the lid is rotated off the pot thatthe latch arms of the legs of the button can be reset to a positionabove the latch dogs of the lock guide. When the lid is rotatedsufficiently so that the lid and pot flanges are no longer one above theother, the lid may be removed from the pot.

[0015] In order to remove the lid from the cooker, the button must bepressed a second time. When the button is pressed a second time, thelatch system permits a downward extending leg of the button mechanicallydepressing the stopbar into its housing slot to permit the lid to berotated off of the cooker.

BRIEF DESCRIPTION OF DRAWINGS

[0016]FIG. 1 is a perspective view of a pressure cooker including ahandle assembly embodying the present invention and showing pressurebeing released from the cooker.

[0017]FIG. 2 is an exploded perspective view of the upper handle of thehandle assembly.

[0018]FIG. 3 is an end view of the handle assembly in the latchedposition with the button and stopbar thereof shown in hidden lines.

[0019]FIG. 4 is a fragmentary side view of the pressure cooker andhandle assembly with the handle assembly in the latched position.

[0020]FIG. 5 is a fragmentary side view of the pressure cooker andhandle assembly with the handle assembly in the pressure releaseposition.

[0021]FIG. 6 is an end view of the handle assembly in the latchedposition with the bodies of the upper and lower handles shown in phantomlines.

[0022]FIG. 7 is an end view of the handle assembly in the pressurerelease position with the bodies of the upper and lower handles shown inphantom lines.

[0023]FIG. 8 is an end view of the handle assembly in the latch releasedposition with the bodies of the upper and lower handles shown in phantomlines.

[0024]FIG. 9 is a fragmentary perspective view of the pressure cookershowing the upper handle rotated away from the lower handle.

DETAILED DESCRIPTION

[0025] The following convention is used in describing various directionswith respect to the inventive cooker. The cooker is assumed to besetting on a counter or other surface in an upright position for normaluse. When the cooker is in this upright, normal orientation, thefollowing terms have the following meanings: The terms “up” or “upward”mean the vertical direction extending from the bottom of the cookertoward the top of the cooker and beyond; the terms “down” or “downward”mean the vertical direction that is the opposite of the “up” or “upward”direction—i.e., the vertical direction extending from the top of thecooker toward the bottom of the cooker; the terms “in” or “inward” meansthe horizontal direction from the periphery or side of the cooker towardthe center of the cooker; and the terms “out” or “outward” means theopposite horizontal direction—i.e., the direction from the center of thepot toward the periphery or side of the cooker. If a part or object is“above” another part or object, the part or object is in a position orlocation that is in the upward direction from the other part or object;thus, the lid of the cooker is above the bottom of the pot of the cookerwhen the cooker is in its normal upright position; similarly if a partor object is “below” another part or object, the part or object is in aposition that is in the downward direction from the other part orobject; thus, the bottom of the cooker is below the lid of the cookerwhen the cooker is in its normal upright position.

[0026] As shown in FIG. 1, pressure cooker 1 has a pot 2 and a lid 3.The pot 2 has an outwardly extending rim 4, which has outward extendingflanges 5 spaced around its circumference. The outward extending flanges5 have lower surfaces 6.

[0027] The cooker 1 has a locking handle assembly 10 and side handles 11and 12. The locking handle 10 comprises a lower locking handle 15 and anupper locking handle 20. The lower locking handle 15 is attached to thepot 2, and the upper locking handle 20 is attached to the lid 3 suchthat, when the cooker is in use, upper locking handle 20 is positionedimmediately above lower locking handle 15, as shown in FIGS. 1, 4 and 5.

[0028] As shown in FIG. 9, the lower locking handle 1 5 is formed with atop surface 16, a guide groove 25 with a curved edge or cam surface 26,and a slot 30. A stopbar 35 having an upper portion 40 is positionedwithin, and spring-biased upward through, the slot 30 so that the upperportion 40 of the stopbar 35 is above the top surface 16 of the lowerlocking handle 15. The upper portion of the stopbar 35 has a curved orcorner 41 and a squared edge or corner 42.

[0029] As shown in FIGS. 3, 4, and 5, the upper locking handle 20comprises a housing 45 that has an interior cavity 55, a lower edge 56,a bottom slot 57 with a right most inner side 58, a elongated slot 59,and an upper opening 60. A spring-biased button 65 fits moveably withinthe upper opening 60 of the upper handle 20 and is spring-biased in anupward position. The button 65 has a downward extending leg 70, whichhas a lower end 71, forms an oval slot 75, and a laterally extendinglatch arm 80. The button 65 also has a downward extending leg 85, whichforms an oval slot 90 and has a laterally extending latch arm 95. Thedownward extending leg 70 is longer than the downward extending leg 85and is positioned on the button 65 so that when the upper locking handle20 is immediately above the lower locking handle 15, the leg 70 isimmediately above the spring-biased stopbar 35 in the lower handle 15.It is preferable to make the downward extending legs 70 and 85 ofmaterial that is somewhat flexible. The button 65 also has a downwardextending rounded tab 100, a downward extending post 105, and a downwardextending block 110.

[0030] As shown in FIGS. 4 and 5, the lid 3 has a downwardly extendingrim 115 having scalloped portions 116, the lower ends 117 of which arebent inward approximately 90 degrees so that the lower bent ends 117 ofthe scalloped potions 116 are substantially horizontal and parallel tothe flanges 5 around the circumference of the rim 4 of the pot 2 whenthe lid 3 is on the pot 2. In this orientation, the lower bent ends 117have upper surfaces 118. A flexible seal 119 fits immediately inside thedownward extending rim 115 and sits on top of the outwardly extendingrim 4 of the pot 2. Posts 120 and 125 are attached to the rim 115proximate the upper handle 20 so that the posts 120 and 125 extendoutward from the rim 115 and through the oval slots 75 and 80,respectively, of the downward extending legs 70 and 75 of the button 65of the upper handle 20. A safety relief valve 130 is secured in the lid3 proximate the upper handle 20 so that an activation plunger 135 of thesafety relief valve 130 extends at outward and upward through the lid 3or the rim 115 of the lid 3.

[0031] As shown in FIGS. 2, 4, and 5, a lockguide 140 is moveablypositioned within the interior cavity 55 of the upper handle 20. Thelockguide 140 has a downward extending guidepost 1 45 that extendsdownward through the elongated slot 59 of the upper handle 20. Thelockguide 140 also has a horizontal inward extending push post 155 and ahorizontal outward extending spring post 156. The Jockguide 140 isspring biased by a spring 157 which is inserted over and around theoutward extending spring post 156 so that the push post 155 is springbiased inward and, when the lid 3 is not installed on the pot 2, extendsthrough a hole 160 in the rim 115 of the lid 3 and abuts the flexibleseal 119 inside the downwardly extending rim 115 of the lid 3. Inaddition, the lockguide 140 has latchdogs 170 and 175 extending fromeach side of an end 180 of the lockguide 140.

[0032] As shown in FIGS. 4 and 6, when the lid 3 is not secured to thepot 2, the stopbar 35 of the lower handle 15 is biased upward, the pushpost 155 and the lockguide 140 (of which push post 155 is a part) arebiased inward, and the button 65 is biased upward.

[0033] In order to secure the lid 3 to the pot 2, the lid 3 isregistered with and placed upon the outward extending rim of the pot 2and rotated clockwise until the upper locking handle 20 is positionedimmediately above the lower locking handle 15. When the lid 3 is rotatedon the pot 2, the upper surfaces 118 of the lower bent ends 117 or thescalloped portions 116 of the lid 3 are in sliding contact with thelower surfaces 6 of the flanges 5 of the rim 4 of the pot 2. See FIGS. 4and 5. When there is pressure in the cooker 1, the lid 3 is subject toan upward force caused by the pressure in the cooker. This upward forceis resisted by the contact between the upper surfaces 118 of the lowerbent ends 117 of the scalloped portions 116 of the lid 3 and the lowersurfaces 6 of the flanges 5 on the rim 4 of the pot 2, which not onlykeeps the lid 3 on the pot 2, but also makes it very difficult to rotatethe lid 3 when there is pressure in the cooker 1 due to the increasedupward force of the upper surfaces 118 of the lower bent ends 117 on thelower surfaces 6 of the flanges 5.

[0034] As the lid 3 is rotated clockwise around the outwardly extendingrim 4 of the pot 2, the downward extending guide 145 of the lockguide140 slides along the curved edge 26 of the guide groove 25 to keep thelid 3 in register with the outwardly extending rim 4 of the pot 2. (SeeFIG. 9) As the downward extending guide 145 of the lockguide 140 slidesalong the curved edge 26 of the guide groove 25, the downward extendingguide 145, and with it the lock guide 140, is moved outward against thebias of the spring 157 on the spring post 156. When lockguide 140 hasmoved outward, the latchdogs 170 and 175 of the lockguide 140 arepositioned directly below or under the latch arms 80 and 95 of thedownward extending legs 70 and 85, respectively, of the button 65, asshown in FIG. 6.

[0035] Also, as the lid 3 is rotated clockwise, the lower edge 56 of theupper locking handle 20 contacts and slides over the rounded edge 41 ofthe stopbar 35, causing the spring-biased stopbar 35 to move downwardinto the slot 30 and allowing the upper locking handle 20 to continue torotated clockwise until it is immediately above the lower locking handle15. (See FIGS. 6 and 9) However, when the upper locking handle 20 isimmediately above the lower locking handle 15, the spring-biased stopguide 35 is directly below the bottom slot 57 of the upper lockinghandle 20, allowing the stopbar 35 to be spring-biased upward into thebottom slot 57 of the upper locking handle 20, as shown in FIG. 6. Whenthe stopbar 35 is spring-biased upward into and within the bottom slot57, the upper locking handle cannot rotate, and, more specifically,cannot rotate counterclockwise to an open position, because, if suchrotation is attempted, the squared edge or corner 42 of the stopbar 35comes into contact with the right most inner side 58 of the bottom slot57, preventing such movement. Thus, when the stopbar 35 is biased upwardinto the slot 57 of the upper locking handle 20, the lid 3 is locked onthe pot 2.

[0036] When the lid 3 is so locked on the pot 2, the lid 3, with the aidof the flexible seal 119, is sealed on the pot 2 so that the contents ofthe pot 2 may be heated and cooking can begin inside the pot 2. As thecontents (typically water and food) of the sealed pot 2 are heated, thetemperature and pressure inside the pot 2 rises, steam may be produced,and the contents of the pot 2 become very hot.

[0037] In order to remove the lid 3 without a rapid and potentiallydangerous escape of the steam and the hot contents of the pot 2, it isnecessary to reduce the pressure inside the pot 2.

[0038] In order to reduce the pressure in the pot 2, the button 65 ispushed downward. As the button 65 is pushed downward, the latch arms 80and 95 of the flexible downward extending legs 70 and 85 of the button65 slidingly pass or snap by the latchdogs 170 and 175 of the lockguide140. When the latch arms 80 and 95 have slidingly snapped or passeddownward by the latch dogs 140, the upwardly spring-biased button 65 isat a first downward position, as shown in FIG. 7. In this position, thelatchdogs 170 and 175 prevent the upwardly spring-biased button 65 fromreturning to the up position (FIG. 6), because, although the button 65is biased upward, the latch dogs 170 and 175 of the lockguide 140 arethen directly above the latch arms 80 and 95 of the legs 70 and 85 ofthe button 65 and prevent the latch arms 80 and 95 from passing by thelatch dogs 170 and 175, thus keeping the button 65 in its first downwardposition and preventing it from returning to its original upwardposition.

[0039] As shown in FIGS. 5 and 7, when the button 65 is pushed downwardto its first downward position, the rounded tab 100 of the of the button65 comes into contact with the activation pin or plunger 135 of thesafety relief valve 130, activating the valve and reducing the pressureinside the pot 2. When the safety relief valve 130 is activated, steam181 escapes through the valve 130 into a channel 185 in the upper handle20, and escapes to the atmosphere through a vent 190 at the end of thechannel 185 in the upper handle 20.

[0040] Moreover, since the rounded tab 100 of the button 65 comes intocontact with the pin or plunger 135 to activate the safety relief valve130 when the button is in its first downward position, and since thelatch dogs 170 and 175 keep the button in its first downward positiononce the button 65 is pressed downward, it will be noted that the tab100 also remains in contact with the pin or plunger 135 and continues toactivate the safety relief valve 130 once the button 65 is presseddownward to its first downward position. Thus, as shown in FIGS. 5 and7, the latch dogs 170 and 175 also prevent the safety relief valve 130from being deactivated (and allowing pressure to again build in the pot2) even if the button 65 is not continually pressed downward. Thus, anoperator simply need press button 65 once to relieve pressure in the pot2.

[0041] Nevertheless, when the button 65 is in its first downwardposition, the lid 3 still cannot be removed from the pot 2. This is sobecause, as shown in FIG. 7, when the button 65 is in the first downwardposition, the stopbar 30 is still spring-biased upward into the bottomslot 57 of upper handle 20, and, accordingly, the lid 3 cannot rotateand is locked on the pot 2.

[0042] In order to unlock and remove the lid 3 from the pot 2, thebutton 65 must be pushed downward farther, or pushed downward a secondtime if the operator has ceased pressing on the button 65 after it is inthe first downward position. As shown in FIG. 8, when the button 65 ispushed down farther (or a second time) the lower end 71 of the longerdownward extending leg 70 of the button 65 comes into contact with theupper portion 40 of the stopbar 35 and forces the upwardly spring-biasedstopbar 30 downward into the slot 30 against the spring biasing ofstopbar 35. When the downward extending leg 70 has pushed the stopbardown into the slot 30 the button 65 is in a second downward position.When the button 65 is in its second downward position and the stopbar 35has been forced downward into the slot 30, the squared edge or corner 42of the upper portion of stopbar 35 is no longer an obstacle to thecounterclockwise movement of the lid 3, and the lid 3 can be rotated andremoved from the pot 2, provided the operator continues to press down onthe button 65 to maintain it in its second downward position. The button65 must be maintained in its second downward position by continuedpressing on the button, because the button 65 is spring-biased upward.If the button 65 is not continuously pressed, the upwardly spring-biasedbutton 65 will return to its first downward position (but will notreturn to its original position due to the position of the latch dogs170 and 175 above the latch arms 80 and 95), and the spring-biasedstopbar 35 will be biased up into the slot 57, thus relocking the lid 3.Thus, downward force must be maintained on the button 65 in order torotate the lid 3 and remove it from the pot 2.

[0043] It will be noted that, when there is pressure in the cooker 1,the upward force on the lid 3 is resisted by the contact between theupper surfaces 118 of the lower bent ends 117 of the scalloped portions116 of the lid 3 and the lower surfaces 6 of the flanges 5 on the rim 4of the pot 2. (See FIGS. 4 and 5) As noted above this resistance notonly keeps the lid 3 on the pot 2, but also makes it very difficult torotate the lid 3 when there is pressure in the cooker 1 due to theincreased upward force of the upper surfaces 118 of the lower bent ends117 on the lower surfaces 6 of the flanges 5. Any attempt to remove ofthe lid 3 from the pot 2 by pressing the button 65 to its seconddownward position and rotating the lid 3 before the pressure in thecooker 1 has been fully relieved will be strongly resisted by theincreased force of the upper surfaces 118 of the lower bent ends 117 ofthe scalloped portions 116 of the lid 3 on the lower surfaces 6 of theflanges 5 on the rim 4 of the pot 2. Thus, premature removal of the lid3 from the pot 2 is significantly more difficult than removal of the lid3 when the pressure in the cooker 1 has been fully relieved; and thepremature removal of the lid 3 from the pot 2, as well as thepotentially dangerous results associated with such premature removal,are much less likely in the inventive cooker 1.

[0044] In order to use the cooker 1, food and other cooking materialsare placed in the pot 2. The lid 3 is then placed on the pot 2 with theupper locking handle 20 to the right of (or in a counterclockwisedirection from) the lower locking handle 15. The lid 3 is then rotatedin a clockwise direction.

[0045] As the lid 3 is so rotated on the pot 2, the following occur:

[0046] (a) the guidepost 145 of the inwardly spring-biased lock guide140 in the upper handle 20 slides along the curved edge 26 of the guidegroove 25 in the lower handle 15, and, as the guidepost 145 slides alongthe curved edge 26 of the guide groove 25, the lock guide 140 is forcedoutward (See FIGS. 5 and 9);

[0047] (b) the upper surfaces 118 of the lower bent ends 117 of thescalloped portions 116 of the lid 3 are in sliding contact with thelower surfaces 6 of the flanges 5 of the rim 4 of the pot 2, as shown inFIGS. 4 and 5;

[0048] (c) the inwardly biased push post 155 of the lockguide 140 hasbeen forced outward and no longer extends inward through the hole 160 inthe rim 115 of the lid 3; and

[0049] (d) the lower edge 56 of the upper locking handle 20 contacts andslides over the rounded edge 41 of the stopbar 35, causing thespring-biased stopbar 35 to move downward into the slot 30 and allowingthe upper locking handle 20 to continue to rotated clockwise toward aposition where the upper locking handle 20 is immediately above thelower locking handle 15, as shown in FIGS. 4 and 6; When the upperlocking handle 20 has been rotated to a position directly above thelower locking handle 15, the following takes place or pertains:

[0050] (e) the spring-biased stopbar 35 is positioned directly below thebottom slot 57 of the upper locking handle 20, and the stopbar 35 isbiased upward into the bottom slot 57, locking the lid 3 on the pot 2,as shown in FIG. 6;

[0051] (f) the latchdogs 170 and 175 of the lockguide 140 are positioneddirectly below the latch arms 80 and 95 of the downward extending legs70 and 85, respectively, of the button 65, as shown in FIG. 6;

[0052] (g) the upper surfaces 118 of the lower bent ends 117 of thescalloped portions 116 of the lid 3 are in contact with the lowersurfaces 6 of the flanges 5 of the rim 4 of the pot 2, as shown in FIGS.4 and 5; and

[0053] (h) the lid 3 is sealed on the pot 2, and cooker 1 may be heatedto cook its food or other contents.

[0054] As the cooker 1 is heated, the following occur:

[0055] (i) the pressure in the pot 2 rises, creating an upward force onthe lid 3 that is resisted by the lower surfaces 6 of the flanges 5 onthe rim 4 of the pot 2 which are immediately above and in contact withthe upper surfaces 118 of the lower bent ends 117 of the scallopedportions 116 of the lid 3, thus keeping the lid 3 on the pot 2; and

[0056] (i) steam and pressurized air are created in the cooker 1 andare, in part, prevented from escaping from the cooker 1 by the flexibleseal 119.

[0057] When the heating and cooking of the cooker 1 have been completed,the button 65 is pressed down, whereupon, the following occurs orpertains:

[0058] (k) the latch arms 80 and 95 of the flexible downward extendinglegs 70 and 85 of the button 65 slidingly snap by and past the latchdogs170 and 175 of the lockguide 140, placing the button in its firstdownward position (FIG. 7), after which the latch dogs 170 and 175 areimmediately above the larch arms 80 and 95 and prevent the upward returnof the latch arms 80 and 95 to their position above the latch dogs 170and 175, which, in turn, prevents the button 65 from returning to itsoriginal position in the upper opening 60 of the upper handle 20;

[0059] (l) as shown in FIG. 5, the rounded tab 100 of the of the button65 comes into contact with the activation pin or plunger 135 of thesafety relief valve 130, activating the valve and reducing the pressureinside the pot 2 by allowing the steam 180 and pressurized air to passthrough the valve 130 into the channel 185 in the upper handle 20 andescape to the atmosphere through the vent 190 at the end of the channel185 in the upper handle 20; due to the position of the latch dogs 170and 175 directly above the larch arms 80 and 95, the latch arms 170 and175 cannot return to their position above latch dogs 170 and 175, andthe button 65 cannot return to its original position above its firstdownward position; accordingly, the tab 100 remains in contact with theplunger or pin 135 of the safety relief valve 130, and the safety reliefvalve remains activated until the cooker 1 is fully depressurized andthe steam the cooker 1 is fully vented; In order to remove the lid 3from the pot 2 after the cooker 1 is depressurized and vented, thebutton 65 is pressed down farther (or a second time) to its secondposition show in FIG. 8. As the button is pushed down to its secondposition, the following occurs:

[0060] (m) the lower end 71 of the longer downward extending leg 70 ofthe button 65 comes into contact with the upper portion 40 of thestopbar 35 and forces the upwardly spring-biased stopbar 30 downwardinto the slot 30 against the spring biasing of stopbar 35, thusunlocking the lid 3 from the pot 2.

[0061] When the lid 3 is unlocked from the pot 2 and the button 65 iscontinuously held in its second position, the lid 3 may be rotatedcounterclockwise to place it in a position where it may be removed fromthe pot 2. When the lid 3 is so rotated counterclockwise, the followingoccurs:

[0062] (n) the downward extending guide post 145 of the lockguide 140slides along the curved edge 26 of the guide groove 25 in a directionopposite to that in which it slid when the lid 3 was being installed onthe pot 3, and as a result, the inwardly biased lockguide 140 movesinward (See FIG. 9);

[0063] (o) the latchdogs 170 and 175 of the lockguide 140 move inwardwith the lockguide 140 and are no longer positioned directly below orunder the latch arms 80 and 95 of the downward extending legs 70 and 85,respectively, of the button 65, thus allowing the upwardly spring-biasedbutton 65 to return to its original position above its first positionand, at the same time, resetting the latch arms 80 and 95 to theiroriginal positions above latch dogs 170 and 175;

[0064] (p) the push post 155 moves inward with the lockguide 140 andmoves inward and through the hole 160 in the rim 115 of the lid 3, whereit contacts the flexible seal 119 and pushes the flexible seal 119 awayfrom the rim 115, thus breaking the sealing action of the seal andallowing any remaining pressurized air or steam to escape from the pot2; and

[0065] (q) the upper surfaces 118 of the lower bent ends 117 of thescalloped portions 116 of the lid 3 sliding move counterclockwise out ofcontact with the lower surfaces 6 of the flanges 5 of the rim 4 of thepot 2, whereupon the lid 3 may be lifted off of the pot 2.

[0066] It is to be understood that while certain forms of the presentinvention have been illustrated and described herein, it is not to belimited to the specific forms or arrangement of parts described andshown.

What is claimed is as follows:
 1. A pressure release handle assembly fora pressure cooker having a pot, a lid securable to the pot, and apressure release valve having an activation pin or plunger, saidpressure release handle assembly comprising: a handle body securable toone of the pot and the lid; a button movably connected to said handlebody, said button having a flexible leg extending therefrom, said leghaving a first latch extending therefrom, and said button further havinga tab extending therefrom, said tab being located adjacent to theactivation pin of the safety relief valve; a second latch connected tosaid handle body, said second latch positioned on said handle body suchthat said first latch may pass by said second latch when said button ismoved, but may not return past said second latch in the oppositedirection; whereby, when said button is moved to a first inwardposition, said tab contacts the pin or plunger of the safety reliefvalve and activates the safety relief valve continuously, beingprevented by the second latch from moving back in the opposite directionto deactivate the safety relief valve.
 2. The pressure release handleassembly as in claim 1 wherein: said handle body is a first handle body;said handle assembly further includes a second handle body securable tothe other of the pot and the lid, said second handle body having agroove formed thereon, said groove having a cam surface; said secondlatch is formed on a lock guide slidably mounted in a cavity formed insaid first handle body, said lock guide further including a guide postextending outwardly from said first handle body through an elongateslot; said guide post being received within said groove in said secondhandle body and biased toward said cam surface when the lid is securedto the pot; and moving said first handle body relative to said secondhandle body causes said cam surface to engage said guide pin and slidesaid guide pin and said lock guide against said bias, said sliding ofsaid lock guide releasing said first latch from said second latch andallowing said bunnton to move back in said opposite direction.
 3. Thepressure release handle assembly as in claim 1 wherein: said handle bodyis a first handle body and said handle assembly further includes asecond handle body securable to the other of the pot and the lid; andsaid handle assembly further comprises a locking mechanism comprising: afirst slot formed in said first handle body in alignment with an end ofsaid flexible leg; a second slot formed in said second handle body; anda stopbar slidably mounted in said second slot and biased outwardlytherefrom; whereby when the lid is secured to the pot, said first slotis aligned with said second slot and said stopbar extends into said saidfirst slot and thereby prevents movement of said first handle bodyrelative to said second handle body; and when said button is moved pastsaid first inward position to a second inward position, said end of saidleg contacts said stopbar and pushes said stopbar back into said secondslot so that the lid may be unsecured from the pot.
 4. A locking handlefor a pressure cooker having a pot and a lid that rotates onto the potuntil the lid is sealed on the pot, said locking handle comprising: alower handle attached to the pot; an upper handle attached to the lid;one of said upper and lower handles forming a first slot; a stopbarmoveably received in said first slot, said stopbar having a first endportion moveable out of said first slot, said first end portion having arounded side; the other of said upper and lower handles having an edgeand forming a second slot to receive said first end portion of saidstopbar; said second slot being aligned with said stopbar when the lidis secured on the pot; a button movably connected to said other handle,said button having a leg extending therefrom, said leg having an endpositioned opposite said first end portion of said stopbar; whereby, asthe lid is rotated onto the pot, the edge of said other handle slidesover said rounded side of said first end portion of said stopbar andpushes said stopbar into said first slot until the lid is in sealingposition, whereupon the first end portion of said stopbar moves intosaid second slot and prevents said upper and lower handles from rotatingwith respect to one another; and whereby, when the button is moved, saidend of said leg of said button contacts said first end portion of saidstopbar and pushes said stopbar back into said first slot so that thelid my be rotated off of the pot.
 5. The handle assembly as in claim 4and further including a pressure release mechanism comprising: apressure relief valve mounted to said pressure cooker proximate saidother handle and having a plunger extending outwardly therefrom; and atab extending from said button, whereby when the button is moved, saidtab contacts said plunger to release pressure from the cooker.
 6. Thehandle assembly as in claim 5 wherein: said leg includes a first latchextending therefrom, said other handle includes a second latchpositioned on said handle such that said first latch may pass by saidsecond latch when said button is moved, but may not return past saidsecond latch in the opposite direction; whereby, when said button ismoved to a first inward position, said tab contacts the plunger of thesafety relief valve and activates the safety relief valve continuously,being prevented by the second latch from moving back in the oppositedirection to deactivate the safety relief valve.
 7. The pressure releasehandle assembly as in claim 6 wherein: said one handle has a grooveformed therein, said groove having a cam surface; said second latch isformed on a lock guide slidably mounted in a cavity formed in said otherhandle, said lock guide further including a guide post extendingoutwardly from said other handle through an elongate slot; said guidepost being received within said groove in said one handle and biasedtoward said cam surface when the lid is secured to the pot; and movingsaid other relative to said one handle causes said cam surface to engagesaid guide pin and slide said guide pin and said lock guide against saidbias, said sliding of said lock guide releasing said first latch fromsaid second latch and allowing said bunnton to move back in saidopposite direction.
 8. A pressure cooker handle assembly for a pressurecooker having a pot and a lid securable thereto, the lid having a safetyrelief valve mounted therein, the relief valve having un upwardlyextending plunger, said handle assembly comprising: a lower handleattachable to the pressure cooker pot, said lower handle forming a slotand having a stopbar moveably received in said slot, said stopbar beingbiased upward in said slot so that an upper portion thereof extendsabove said slot; said upper portion of said stopbar having a roundedside and a straight side; an upper handle attachable to the pressurecooker lid, said upper handle forming a bottom slot and an inner cavityfor receiving a moveable lock guide said lock guide having a latch dogextending from a side thereof; said upper handle further having a buttonmoveably secured in an upper opening of said upper handle, said buttonhaving a downward extending tab and a downward extending leg having alatch arm; whereby when said upper and lower handles are attached to thelid and pot respectively and the lid is placed on the pot and said upperhandle is rotated in a first direction toward a position immediatelyabove said lower handle, an edge of said upper handle slidingly contactssaid curved edge of said stopbar, pressing said stopbar downward intosaid slot in said lower handle and permitting said top handle tocontinue to rotate to said position immediately above said lower handle,in which said position: said bottom slot of said upper handle is alignedabove said stopbar, and said stopbar is biased up into said bottom slotof said upper handle, preventing said upper handle from rotating out ofalignment above said lower handle; said tab of said button is alignedimmediately above the plunger of the safety relief valve; and saiddownward extending leg of said button is aligned immediately above saidstopbar; when said button is pressed downward a first time, said tab ofsaid button presses the plunger of the safety relief valve, releasingpressure in the cooker; and when said button is pressed downward asecond time, said downward extending leg of said button pushes saidstopbar of said lower handle down into said slot in said lower handle,permitting said upper handle and said lid to be rotated in a directionopposite said first direction away from and out of alignment immediatelyabove said lower handle so that said lid can be removed from said pot.9. A pressure cooker comprising: a lid securable to a pot, said lidhaving a rim, said rim defining a hole and having two laterallyextending posts connected thereto; a safety relief valve connected tosaid lid, said safety relief valve having an activation plunger thatactivates said safety release valve when said plunger is pressed; alower handle connected to said pot, said lower handle defining a groovein a top surface thereof and a slot, a moveable stopbar spring biasedupwardly through said slot in said lower handle, an upper handleattached to said lid, said upper handle defining an upper opening, alower edge, a first bottom slot, a second bottom slot, a side hole, andan internal cavity, a lock guide having an inward extending push postand a downward extending guide post, said lock guide being positioned insaid internal cavity such that said push post is spring biased throughsaid side hole in said upper handle and said hole in said rim of saidlid and said guide post extends through said second bottom slot in saidupper handle, and a button having a downward extending tab and downwardextending legs, said legs each forming a slot, said lateral extendingposts of said rim of said lid extending through said slots in saiddownward extending legs, whereby as said upper handle and said lid arerotated toward a position immediately above said lower handle, saidstopbar is pushed downward into said slot in said lower handle to permitsaid top handle to continue to rotate to a position immediately abovesaid lower handle, and as said upper handle is further rotated to aposition immediately above said lower handle, said first bottom slot ofsaid upper handle is aligned above said stopbar, and said stopbar isbiased up into said first bottom slot of said upper handle, preventingsaid upper handle from rotating out of alignment above said lowerhandle; said tab of said button is aligned immediately above saidplunger of said safety relief valve; and said downward extending leg ofsaid button is aligned immediately above said stopbar; whereby, whensaid button is pressed downward a first time, said tab of said buttonpresses the plunger of the safety relief valve, releasing the pressurein the cooker; and when said button is press downward a second time,said downward extending leg of said button pushes said stopbar of saidlower handle down into said slot in said lower handle to permit saidupper handle and said lid to be rotated out of alignment immediatelyabove said lower handle so that said lid can be removed from said pot.10. A handle assembly for a pressure cooker having a safety reliefvalve, said handle assembly comprising: a lower handle having a stopbarmoveably secured in a slot in said lower handle, said stopbar beingbiased upward by a spring, an upper handle having: a button moveablysecured, and spring biased upward, in an opening formed in said upperhandle; said button having a downward extending tab and a downwardextending leg; said leg having a latch arm extending from a sidethereof; and a lock guide moveably secured in an internal cavity of saidupper handle, said lock guide having a latch dog extending from a sidethereof; whereby when said upper handle is positioned immediately abovesaid lower handle, said downward tab of said button is alignedimmediately above an activating plunger of the safety relief valve, anend of said downward extending leg is aligned immediately above saidstopbar, said latch arm is aligned immediately above said latch dog,said slot in said upper handle is aligned immediately above saidstopbar, and said stopbar is biased upward into said slot in said upperhandle; when said button is pressed downward a first time, said downwardextending tab presses said plunger of said safety relief valve,releasing pressure in said pressure cooker, and said latch arm movespast said latch dog preventing said button from returning upward; andwhen said button is pressed downward a second time, said end of saiddownward extending leg of said button pushes the stopbar down into saidslot in said lower handle so said upper handle can be moved out ofalignment with said lower handle and said lid can be removed from saidpot.